Multilayer diamond display system and method

ABSTRACT

Disclosed herein is a transparent glass system that includes an optical grade silicon substrate, a transparent substrate layer; a titanium dioxide transparent layer, the transparent layer having an index of refraction of 2.35 or greater; and a polycrystalline diamond layer, wherein the transparent layer is between the substrate layer and the polycrystalline diamond layer.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No.62/429,769, filed Dec. 3, 2016, which is fully incorporated herein byreference.

BACKGROUND Field

This invention is generally related to systems and methods fortransparent diamond electronics, and more particularly to a system andmethod for providing a multilayer diamond display system.

Background

Diamond possesses favorable theoretical semiconductor performancecharacteristics, including the possibility of creating transparentelectronics, including those related to consumer electronic componentmaterials, such as display and lens materials. These applications ofteninclude more stringent design requirements, such as increased hardness,scratch resistance, and water resistance. However, practical diamondbased semiconductor device applications for consumer electroniccomponent materials remain limited.

SUMMARY

Disclosed herein is a new and improved system and method for amultilayer diamond display system. In accordance with one aspect of theapproach, a multilayer diamond display system may include an opticalgrade silicon substrate, a transparent substrate layer; a titaniumdioxide transparent layer, the transparent layer having an index ofrefraction of 2.35 or greater; and a polycrystalline diamond layer,wherein the transparent layer is between the substrate layer and thepolycrystalline diamond layer.

In another approach, a method of fabricating a multilayer diamonddisplay system may include the steps of selecting a substrate, forming afused silica and titanium dioxide layer on the substrate, forming afused silica layer on the fused silica and titanium dioxide layer,forming a titanium dioxide transparent layer on the fused silica layer;and forming a nanocrystalline diamond layer on the titanium dioxidelayer.

Other systems, methods, aspects, features, embodiments and advantages ofthe system and method disclosed herein will be, or will become, apparentto one having ordinary skill in the art upon examination of thefollowing drawings and detailed description. It is intended that allsuch additional systems, methods, aspects, features, embodiments andadvantages be included within this description, and be within the scopeof the accompanying claims.

BRIEF DESCRIPTION OF THE DRAWINGS

It is to be understood that the drawings are solely for purpose ofillustration. Furthermore, the components in the figures are notnecessarily to scale, emphasis instead being placed upon illustratingthe principles of the system disclosed herein. In the figures, likereference numerals designate corresponding parts throughout thedifferent views.

FIG. 1 is an exemplary schematic diagram of a fabrication process for amultilayer diamond display system.

FIG. 2 is an exemplary block diagram of an embodiment of a method forfabricating a multilayer diamond display system, such as the displaysystem of FIG. 1 .

FIG. 3 is a further exemplary schematic diagram of a fabrication processfor a multilayer diamond display system.

FIG. 4 is graphical transmission spectra that may be produced usingfabrication processes described herein, such as the processesillustrated in FIG. 2 and FIG. 3 .

FIG. 5 is a schematic representation of an embodiment of a display glassmultilayer diamond system that may be produced using fabricationprocesses described herein, such as the processes illustrated in FIGS. 13.

FIG. 6 is a table providing comparisons between the prior art materialsand systems that may be produced using fabrication processes describedherein, such as the embodiment illustrated in FIG. 5 .

FIG. 7 is a schematic representation of another embodiment of amultilayer diamond system having interior and exterior diamondmultilayers that may be produced using fabrication processes describedherein, such as the processes illustrated in FIGS. 1 3.

FIG. 8 is a schematic representation of another embodiment of amultilayer diamond system having a monolithically integrated diamondcapacitive layer that may be produced using fabrication processesdescribed herein, such as the processes illustrated in FIGS. 1 3.

DETAILED DESCRIPTION

The following detailed description, which references to and incorporatesthe drawings, describes and illustrates one or more specificembodiments. These embodiments, offered not to limit but only toexemplify and teach, are shown and described in sufficient detail toenable those skilled in the art to practice what is claimed. Thus, forthe sake of brevity, the description may omit certain information knownto those of skill in the art.

The system and method provided herein allow for a novel diamond basedmultilayer antireflective coating system and a novel method for infraredoptical windows. FIG. 1 shows an exemplary schematic diagram 100 of afabrication process for a multilayer diamond display system. Diagram 100includes a substrate material layer 102, a thin film composite layer104, and a diamond layer 106. Substrate material layer 102 may include atransparent substrate, such as, but not limited to, aluminosilicateglass, for example, Corning Gorilla Glass® 3, commercial glass, forexample, BK7, fused silica, quartz, sapphire, indium tin oxide, titaniumdioxides, such as, but not limited to, crystalline rutile, in additionto others known to those having ordinary skill in the art. Any of theaforementioned materials, as well as combinations thereof, may beincluded in substrate layer 102.

The thin film composite layer 104 may include a transparent materialwith an index of refraction of 2.35 or greater. In one embodiment,titanium dioxide may be deposited on the substrate layer 102 via, forexample, but not limited to, physical vapor deposition (PVD) sputteringor reactive ion deposition. In some embodiments, the first thin filmlayer may have an index of refraction ranging from 2.6 to 2.8.Crystalline titanium dioxide may be used in forming thin film compositelayer 104. The thin film layer 104 may include lower refractive indextransparent materials to favor transmission at blue, green, and redwavelength ranges. The thin film composite layer 104 may use materialsoptimized for operating wavelengths for blue light between 440 and 470nm, green light between 510 and 550 nm, and red light between 600 and640 nm wavelengths.

The diamond layer 106 may be fabricated by processes including seedingwith a nanocrystalline diamond solution mixture. Fabrication of thediamond layer 106 may include acid cleaning, for example, via piranhaand ionic clean methods. Fabrication of the diamond layer 106 mayinclude ultrasonic roughening to facilitate more uniform and strongcohesion of growth diamond material. Fabrication of the diamond layer106 may include chemical vapor deposition techniques, such as, but notlimited to Hot Filament and Microwave Plasma methods. In one embodiment,nanocrystalline diamond materials may be formed under vacuum conditionsusing Methane, Hydrogen, and Argon gas.

FIG. 2 shows an exemplary block diagram of an embodiment of a method 200for fabricating a multilayer diamond systems, such as, but not limitedto, the display system of diagram 100. Method 200 may include a step 202of selecting a substrate material, such as an optical grade substrate,for example, the substrate of substrate material layer 102.

Method 200 may include a step 204 of depositing a thin film layer, suchas, but not limited to thin film composite layer 104. Method 200 mayinclude a step 206 of cleaning a seeding where the surface of thesubstrate may be acid cleaned, for example, via piranha and ionic cleanmethods, and ultrasonically roughened to facilitate more uniform andstrong cohesion of growth diamond material. In step 206, the substratemay be seeded with a nanocrystalline diamond solution mixture.

Method 200 may include a step 208 of exposing the substrate to gas. Step208 may include a cooled substrate wafer stage to maintain temperaturesat or below 500 degrees Celsius allowing multilayer integration withoutexceeding stress, softening, and strain limitations of the underlyingmaterial layers. The diamond growth process energy is substantiallyderived from thermally activated filament sources or microwave activatedplasma sources. Method 200 may include a step 210 of finishing amultiplayer diamond display system. Step 210 may include surfacetreatment, surface polishing, and packaging.

FIG. 3 shows another exemplary schematic diagram 300 of a fabricationprocess for a multilayer diamond display system. Diagram 100 includes asubstrate material layer 302, a first thin film composite layer 304, afused silica layer 306, a titanium dioxide layer 308, and a diamond toplayer 310. Substrate material layer 302 may include a transparentsubstrate, such as those described in regard to substrate material layer102.

The first thin film composite layer 304 may include fused silica andtitanium dioxide producing a refractive index of about 1.75. Thetitanium dioxide layer 308 may have a refractive index values in therange of 2.6 to 2.8, but with a minimum value of 2.35. The diamond toplayer 310 may be formed as described in regard to diamond layer 106.

FIG. 4 shows a graphical transmission spectra 406 that may be producedusing fabrication processes described herein, such as the processesillustrated in FIG. 2 and FIG. 3 . Graph 400 includes a horizontal axis402 illustrating light wavelengths, and vertical axis 402 illustratinglight wave transmission, through a system fabricated according to thetechniques illustrated in FIG. 3 , where the system includes: (a) afused silica/titanium oxide layer, such as first thin film compositelayer 304, of 44 nm; (b) a fused silica layer, for example, fused silicalayer 306, of 186 nm; (c) a titanium dioxide layer, for example,titanium dioxide layer 308, of 67 nm; and (d) a diamond top layer, forexample diamond top layer 310, of 40 nm. In spectra 406 thetransmittance at the peak wavelengths are shown to be 89.7%, 86.2% and87.1% for blue, green and red, respectively, yielding overalltransmittance between 88-89%. This high level of transmittance isvisually indistinguishable from present mobile and wearable display Massspecifications of 92% in this wavelength range, such as standard CorningGorilla Glass® 5. Increasing the number of multilayers may increase thetransmittance beyond these values, Glass layers may be interspersed withother layers in order to tune transmittance peaks to desired visiblewavelengths.

FIG. 5 is a schematic representation 500 of an embodiment of a displayglass multilayer diamond system that may be produced using fabricationprocesses described herein, such as the processes illustrated in FIGS. 13. Representation 500 includes a rigid chassis layer 502, a flexibleorganic light emitting diode layer 504, a capacitive touch layer 506,interior lens glass layer 508, and an exterior glass lens layer 510. Therigid glass layer 502 may be, for example, include aluminum. Thecapacitive touch layer 506 may be include indium tin oxide and fusedsilica. The interior lens glass layer 508 may include Gorilla Glass.Exterior glass lens layer 510 may be formed by including systems andmethods illustrated in FIGS. 1 and 2 . Diamond multilayer structures,such as those illustrated by schematic 500, may provide desirablestrength and hardness features which may operate with reduced thermalbudget via higher thermal conductivity. Such strength and hardnessfeatures are illustrated in table 600, shown in FIG. 6 , where featuresfor representation 500 are shown in the bottom row. In table 600,nanocrystalline diamond is approximately 200 nanometers and the fusedsilica glass is approximately 500 microns.

FIG. 7 is a schematic representation 700 of another embodiment of amultilayer diamond system that may be produced using fabricationprocesses described herein, such as the processes illustrated in FIGS. 13. Representation 700 includes a rigid chassis layer 702, a flexibleorganic light emitting diode layer 704, a capacitive touch layer 706,and an exterior glass lens layer 708. Representation 700 may allow forthe combination, or elimination, of an interior lens, such as interiorlens 508 of representation 500. Exterior glass lens layer 708 may beformed by is systems and methods illustrated in FIGS. 1 and 2 .

FIG. 8 is a schematic representation 800 of another embodiment of amultilayer monolithically integrated diamond system that may be producedusing fabrication processes described herein, such as the processesillustrated in FIGS. 1 3. Representation 800 includes a rigid chassislayer 802, a flexible organic light emitting diode layer 804, and anexterior glass lens layer 506. Exterior glass lens layer 506 may beformed by including systems and methods illustrated in FIGS. 1 and 2 .Representation 800 may allow for a multi layer diamond system of lessthan 0.5 millimeters. In representation 800, the capacitive touch layermay be incorporated as substrate layer. Representation 800 may provide amulti layer monolithically integrated diamond display module withmechanical, optical, and thermal tolerances meeting or exceeding displayapplication demands.

The multilayer diamond display system described, and method 200, mayincorporate systems and methods previously disclosed and described inU.S. Patent Publication No. 2013/0026492, by Adam Khan, published onJan. 31, 2013; U.S. Pat. No. 8,354,290, issued to Anirudha Sumant, etal, on Jan. 15, 2013; U.S. Pat. No. 8,933,462, issued to Adam Khan onJan. 13, 2015; U.S. Patent Publication No. 2015/0206749, by Adam Khan,published on Jul. 23, 2015; and U.S. Patent Publication No.2015/0295134, by Adam Khan, et al, published on Oct. 15, 2015, all ofwhich are fully incorporated herein by reference.

This disclosure provides several preferred embodiments of fabrication,however, the performance characteristics and materials characteristicsdescribed in this application are not necessarily performance bounds orlimitations of the invention. These disclosures merely demonstrate someaspects of the invention that have presently been tested.

The word “exemplary” is used herein to mean “serving as an example,instance, or illustration.” Any embodiment or variant described hereinas “exemplary” is not necessarily to be construed as preferred oradvantageous over other embodiments or variants. All of the embodimentsand variants described in this description are exemplary embodiments andvariants provided to enable persons skilled in the art to make and usethe invention, and not necessarily to limit the scope of legalprotection afforded the appended claims.

The above description of the disclosed embodiments is provided to enableany person skilled in the art to make or use that which is defined bythe appended claims. The following claims are not intended to be limitedto the disclosed embodiments. Other embodiments and modifications willreadily occur to those of ordinary skill in the art in view of theseteachings. Therefore, the following claims are intended to cover allsuch embodiments and modifications when viewed in conjunction with theabove specification and accompanying drawings.

We claim:
 1. A multilayer diamond display system, comprising: a chassislayer; an organic light emitting diode layer; a capacitive touch layer;and a diamond composite exterior lens, including: a fused silica layer;a crystalline diamond layer; and a titanium oxide transparent layerbetween the fused silica layer and the crystalline diamond layer.
 2. TheA multilayer diamond display system of claim 1, wherein the titaniumoxide transparent layer comprises a titanium oxide transparent layerhaving an index of refraction of 2.35 or greater.
 3. The multilayerdiamond display system of claim 1, wherein the diamond compositeexterior lens further includes a substrate layer and a fused silica andtitanium dioxide layer, wherein the fused silica and titanium dioxidelayer is between the substrate layer and the fused silica layer.
 4. Themultilayer diamond display system of claim 3, wherein the fused silicaand titanium dioxide layer comprises a fused silica and titanium dioxidelayer having an index of refraction ranging from 2.6 to 2.8.
 5. Themultilayer diamond display system of claim 1, wherein the capacitivetouch layer comprises indium tin oxide and fused silica capacitive touchlayer.
 6. A multilayer diamond display system, comprising: an organiclight emitting diode layer; a capacitive touch layer; and a diamondcomposite exterior lens, including: a fused silica layer; a crystallinediamond layer; and a titanium oxide transparent layer between the fusedsilica layer and the crystalline diamond layer.
 7. The A multilayerdiamond display system of claim 6, wherein the titanium oxidetransparent layer comprises a titanium oxide transparent layer having anindex of refraction of 2.35 or greater.
 8. The multilayer diamonddisplay system of claim 6, wherein the diamond composite exterior lensfurther includes a substrate layer and a fused silica and titaniumdioxide layer, wherein the fused silica and titanium dioxide layer isbetween the substrate layer and the fused silica layer.
 9. Themultilayer diamond display system of claim 8, wherein the fused silicaand titanium dioxide layer comprises a fused silica and titanium dioxidelayer having an index of refraction ranging from 2.6 to 2.8.
 10. Themultilayer diamond display system of claim 6, wherein the capacitivetouch layer comprises an indium tin oxide and fused silica capacitivetouch layer.